Ophthalmic lens



April 21, 1931. E. KLEIN ET AL OPHTHALMIC LENS FiledSept. 2'7, 1928 a vw H Wm: I. J:

elements going into the preparatioi of a part Patented Apr. 21. 1 931 UNITED STATES PATENT OFFICE sorrow-nu, or roar moms,

ornrrmnmc mans Application filed Septeinber 27, 1928. Serial No. 808,721.

This invention relates to ophthalmic blanks and lenses and has for an object the provision of a lens with a plurality of focal powers.

Another object is to provide an ophthalmic lens blank of the type referred towhich is simpler and less expensive to manufacture than heretoforeknown lenses for such purposes. 1

Another object isto provide an ophthalmic lens blank for the purposes stated which is adapted to be ground on any curve or combination of curves which may be required for a given correction.

Another object is toprovide a fused blank for ophthalmic lenses wherein the likelihood of disturbing elements in the lens due to the fusing process is reduced to a negligible .amount.

Another object is to rovide a means and method for making a sed lens providing portions of different power and wherein the oinder or fusion of said portions is practically invisible.

the method set forth and the means described herein. and shown inthe accompanying drawings, in which:

Fig. 1 is a cross sectional view of the,

of the lens of the invention. I

Fig. 2 is a cross sectional view of such part after preparation andv prior to grinding.

Fi 3 is a cross sectional view of a part forming a detail of the invention.

Fig. 4 is the fragmental cross sectional view of a lens blank ground to receive the part shown in Fig. 3.

Fig. 5 is a cross sectional View of the completed blank, part being broken away.

Fig. 6 is a view of a completed lens formed from a lens blank such as is shown in Fig. 5.

Fig.

taken on line 7-7 of Fig. 6.-

The ophthalmic lens of the invention com-.

prises a specially prepared button.' or disk, indicated generally as 10, as is shown 1n cross section in Fig. 3 and. a lens blank 11 These and other objects are attained by.

7 is an enlarged cross sectional view to whichpthe prepared button is fused in the manner usually employed in the manufacture of Kryp particularly that the blank 11 is heated but once in order to fuse the button 10 thereto. and that this single heating of the large blank is highly advantageous over a plurality of fused heats to which heretofore is true because the heat vibrations as well aspossible other vibrations which occur dur greatly reduced as the size of the piece of glass is reduced.

Referring now to the prepared button 10 it will be noted from Fig. '1 that a small disk or block. of optical glass 12 has a recess 1'3 ground'therein into which a piece of spectacle glass 14, ground as at 15 in sub tok blanks. It isto be noted proposed lenses have been subjected. This J stantial conformity to the recess 13 is seated.

These parts are shown in Fig. 1. It is to be understood that these parts are quite small. The disks or parts 12 and 14 prepared as shown in Fig. 1, are thensubmitted to a fusing heating to unite. them" so that the rough button shown in Fig. 2' results, and comprises a smaller portion 14 of ordinary spectacle glass and the larger united button shown in Fig. 2 is thenv ground to y i assume a cross sectional shape as shownin' Fig. 3 and constitutes the completed pre-' pared button 10. A full sized blank 11 of ordinary spectacle glass, similar to the'por;

tion 14, is then recessed as at 16 so as to. receive the prepared button 10. The pre pared button 10 and the suitabl recessed spectacle blank 11 are thencfuse together at a single heating whereupon there isprovided a commercial blank which may be ground according tothe needs of a wearer,.

either as a spherical lens, cylindrical lens 1 or prismatic lens or any combination of two or all of them. This is true because the portion 12 is the optical glass of higher index of refraction and is exposed on the outer face of the lens and that the small portion 14 of ordinary spectacle glass has now united with the blank 11 of similar ordinary spectacle glass and is wholly concealed and entirely invisible within the body of the completed lens. It is to be noted that numerous of the proposed fused lenses providing for a plurality of focal powers or a plurality of fields of vision are practical only when they are prepared into a spherical lens so that it was necessary to sacrifice the advantage of a proper correction in certain cases in order to provide for the several different fields of vision in one lens.

Referring now to Figs. 6 and 7 it will be noted that the large field 17 will be wholly the ordinary spectacle glass and will constitute the large field for distant vision; the somewhat crescent shaped field 18 will be through the portion 12 or the optical glass of a higher index of refraction, the power of which is increased or decreased by the grinding of the external curves on.

the finished lens. The field 19 is of a reduced power due to the original spherical depression 13 formed in the optical glass 12. This field 19 in the ophthalmic lens of the present invention may thus provide a field which is uniform with the field 17 or which may provide a field of a strength intermediate that of the reading field 18 and the distance field 17. This latter arrangement is found highly desirable for those who have occupations which require looking down at their work through a field which is preferably disposed at the bottom of the lens. Examples of desirable use of such a lens might be found in playing golf, where the player desires to have a very distinct view of the ball on the ground before him but finds it too far away to be properly seen through the readin portion of his lens. Another use would be or the housewife in doing work which is preferably held on her lap. Particularly in ironing is the lens of the invention valuable to the housewife.

Thus in summarizing the advantages of the ophthalmic lens of the invention and the method of making it it will be noted that the steps of manufacture as outlined all tend to minimize to a'negligle amount the imperfections attending the manufacture of heretofore proposed lenses, thus rendering the cost of manufacure as well as the care and skill in the process less expensive and difficult. The resultant blank is adapted for commercial distribution as such for grinding into a finished lens by any skilled optician and according to any prescription. The most complicated of prescriptions for single piece lenses will present no difficulties in grinding from the blanks of the present invention. The finished lens is without disturbing elements. The joinder of parts of the lens is practically invisible, and the blank is capable of commercial distribution v in the manner impossible with heretofore proposed lenses of the inulti-focal type so that a pair of spectacles of the multi-focal type may be prepared'or repaired by any lens grinding optician'as quickly and with no more difiiculty than the same Optician would prepare a simple lens. This is due to the disposition of the convex curve 20 and concave curve 13 of the optical glass member 12 interiorly of the completed blank.

What is claimed is:

A lens blank of the class described comprising a major blank of spectacle glass countersunk eccentrically on one face and a prepared member fused into said countersunk recess, the prepared member comprising a relatively large piece of optical glass of a higher index of refraction one face of which is in part concaved and filled with spectacle glass, the remaining part of said face and the filled in portion of the spectacle glass being formed with a continuous convex curve substantially complementary to the countersunk recess in the major blank and secured therein.

In testimony whereof, we have hereunto subscribed our names this 25th day of September, 1928.

- EMANUEL KLEIN.

THEODORE SCI-IQEN-ER. 

